1. Field of the Invention
This invention relates generally to machine tools, and more particularly to an improved means for supporting and guiding two components thereof during sliding movement of one on the other.
2. Description of the Prior Art
In prior art machine tools, one mounting technique commonly used has been to provide parallel guideway bars bolted to one part of the machine tool (the bed, for example) and gib rails fastened to a slide (worktable, for example). Shims or wedges have been secured between the gib rails and the slide for periodic adjustment to compensate for wear and avoid looseness.
Other slide and guide arrangements are known.
The U.S. Pat. No. 1,835,328 to Parsons, shows a knee-type milling machine. Gib 14 is said to be tapered. There is an adjusting screw 14a (FIGS. 2 and 4) whereby the gib is adjusted to fit closely between the opposed surfaces throughout its length, but loose enough to permit the saddle to slide. Similarly, a tapered gib 20 and adjusting screw 15a are provided.
A U.S. Pat. No. 1,917,926 to Decker mentions some prior art techniques intended to avoid the necessity for frequent and careful screw adjustment of gibs to take up the wear and play between the parts. It mentions springs and plungers spaced along a gib, and proposes a continuous spring as a preferred solution.
There remains a need for a self-adjusting gib which is inexpensive, resistant to displacement under heavy or shock loads or vibrations while, nevertheless, accommodating the desired sliding movement without undue resistance. The present invention is directed to meeting this need and has these advantages over the prior art known to me.